Annual or perennial herbs or shrubs. Corolla papilionaceous with free standard and wings, the two keel petals connate; nine stamens united by their filaments forming a staminal column, the tenth stamen free; corolla and the staminal column forming a tripping mechanism for cross-pollination. Calyx bell-shaped, 5-toothed. Leaves trifoliate. Stipules adnate to the petiole. Racemes axillary, pedunculate, few-to-many-flowered. Fruit from a straight to a tightly coiled pod. Seeds 1-to-many per pod. Cotyledons at seedling stage not divided into separate petiolar and laminar parts. Basic chromosome number x = 8, some species have x = 7.